EPS and DEAD atoms cannot be recognized by fix

[shelllbw]

If any fix command uses "group-ID" containing EPS or DEAD type, make sure such "group-ID" is specified in fix nufeb/eps_extract or fix nufeb/death/diameter. Otherwise, the corresponding EPS or DEAD atoms cannot be recognized by the fix. For example:

#type 2 (eps) is assigned into two groups
group het type 1
group eps type 2
group mix 1 2

#only group "eps" is specified in fix nufeb/eps_extract, secreted EPS will not be assigned to `mix` group
fix eps_ext het nufeb/eps_extract 2 eps .....

#ERROR! fix nve cannot apply to EPS atoms
fix nve mix nve/limit 1e-7

#SOLUTION: use the group-ID specified in fix nufeb/eps_extract
fix nve het nve/limit 1e-7
fix nve eps nve/limit 1e-7